The present invention relates to an apparatus for automatic measuring for water toxicity. More specifically, the present invention provides an apparatus measuring water toxicity and/or contamination continuously and automatically using luminescent microorganisms living in freshwater.
A method using luminescent microorganisms is known to measure water toxicity and/or contamination. The luminescent mechanism of the luminescent microorganism is affected by activation of biochemical environmental conditions of the luciferase that controls the emission of light, resulting in changing luminosity of the microorganism. The Microtox Assay System (hereinafter, MAS) commercialized by the MICROBICS Co. is an apparatus measuring water toxicity and/or contamination using luminescent microorganisms. The MAS method measures the luminosity of light emitted by luminescent microorganism under toxic conditions on the basis of the luminosity of the luminescent microorganism living non-toxic conditions. The measuring value of MAS is EC50 that represents concentration of toxic chemicals causing 50% reduction of luminosity.
However, because seawater microorganisms are used in MAS system, a separate addition of salts into a test sample in an amount equivalent to that of seawater is required to show physiological function of luminescent microorganisms. In this case, toxicity of chemicals may be offset due to the reaction of chemicals with metals and salts. As a result while most parts of the MAS data show similar results with those obtained from measurements using other microorganisms, the MAS toxicity data do not align with those obtained from measurements using other microorganism, for toxic chemicals such as ammonia or cyanide.
In addition, in order to measure toxicity of samples using MAS, lyophilized microorganisms contained in each ampoule need to be rehydrated one by one, and then are mixed with aqueous sample before their luminescence is measured by luminometer. Furthermore, MAS requires a batch operation system, wherein an operator measures luminescence of each individual sample manually. Therefore, in order to measure and observe the water toxicity continuously and continuously using a MAS method, an ampoule containing luminescent microorganisms needs each measuring time, which necessitate an operator for an apparatus measuring toxicity. Due to these problems, it has been a very laborious work to measure water toxicity continuously using the currently available apparatuses. Therefore, continuous monitor of water toxicity was almost impossible with any methods that have been developed up to now for the purpose of measuring water toxicity. Until the present invention, an automatic apparatus for measuring and monitoring water toxicity has never been developed. Despite of necessity and importance of continuous and automatic monitoring of water toxicity, automatic measurements are limited for pH, DO, water level, flow rate, and the like. Automatic measuring and monitoring of COD and SS is reported to be partially available for several limited samples.
Moreover, an environmental monitoring system is mainly limited to air pollution field. Thus, in water field, only monthly monitoring has been done in each water system, and continuous and automatic system for measuring and monitoring water pollution has not yet been commercialized.
Therefore, the present invention provides an apparatus for automatic and continuous measuring of water toxicity, comprising
A sample supplier for gathering test samples from water system at regular intervals and continuously, and for supplying test samples to luminescent microorganisms;
a multi-well plate containing luminescent microorganisms, wherein the top of the well is sealed with gas-impermeable film;
a storage unit for multi-well plate, which sequentially supplies multi-well plates, wherein each well contains, lyophilized luminescent microorganisms;
a transportation means for said multi-well plates;
an injection needle for providing test samples and reagents in an accurate amount into luminescent microorganism contained said multi-well plate;
a sensor for detecting luminosity after a lapse of certain times from injection of samples and reagents into luminescent microorganisms; and
a control unit for electrical or mechanical control or regulation of an automatic operation of said each unit.
In addition, the apparatus of the present invention may further comprises a temperature control unit that controls and/or maintains constant temperature inside of the apparatus.
Therefore, one aspect of the present invention is to provide an apparatus capable of measuring water toxicity continuously without an operator.
Another aspect of the present invention is to provide a multi-well plate containing luminescent microorganisms, wherein top of the well is sealed with gas-impermeable film.